A solid fuel combustion equipment with an upward combustion system is disclosed in Japanese Laid Open Patent Application No. 231307/1984, in which a combustion unit provided on a distillation unit for converting a solid fuel to a distillation gas. A heat exchange unit at the upper part thereof to generate a distillation gas at the lower part thereof and to burn this gas as it rises through the heat exchange unit. An air supply means delivers a small quantity of air at the bottom portion of the distillation unit. It is seen from the figure that an upward air-supply opening is bored at the bottom portion thereof.
While it can be said that the above-described equipment is, in principle, a sort of dry distillation gasification combustion equipment, it is only a structure in which the dry distillation unit and the combustion unit are continuous in upper and lower directions It is not of a structure in which both units are clearly partitioned.
When attention is drawn to the dry distillation unit of this equipment, insufficient consideration is given to generation efficiency of the dry distillation gas and to making the dry distillation gasification process as clean as possible. Therefore, environmental problems such as the generation of soot and smoke or dust, or odor remained unsolved.
The few bored air supply holes bored in the bottom of this unit tend to become choked or clogged up with ashes from the combustion taking place therein. Consequently, unstable performance of the apparatus reduces the production efficiency of the dry distillation gas, or stoppage of production of the distillation occurs.
To continue operation, an operator must clean out the small air supply holes by inserting a driver, or the like, into individual holes to scrape away ashes therefrom. This is tedious work, and its necessity substantially reduces the effectiveness of the equipment.
As stated above, the conventional equipment is unsatisfactory in its efficiency in the production of dry distillation gas, the generation of clean dry distillation gas, and in its performance stability. In addition, the difficulty in cleaning and maintenance are substantial drawbacks.
Further the combustion unit of this prior-art unit burns dry distillation gas only within a broad combustion chamber wherein dry distillation gas is mixed with air together with soot and smoke or dust, etc. Accordingly, it is impossible to adjust combustion to attain complete, clean, combustion.
A gasification fuel combustion equipment for burning gasified fuel obtained by means such as dry distillation, etc. is disclosed in Japanese Patent Publication No. 29365/1990. This equipment is common to the equipment of the invention of this application in the sense that combustion equipment of the burner system is adapted for completely burning a fuel once gasified by dry distillation or other means.
However, since this prior art uses a rectification cylinder within a cylindrical combustion chamber, thus to agitate and mix air blown off from small holes with combustion gas, this equipment is satisfactory at the beginning of use, but such holes become clogged after a little use. Further, the internal structure is complicated, and its cleaning and/or maintenance are very difficult.